Cars have titles that allow the leasing company to maintain contractual ownership of the car in order to secure the lease cleanly, efficiently, and cheaply. Aftermarket parts do not have titles. The cost to document an aftermarket parts lease just wouldn't be practical (each transaction would be custom).

I see many posts with leasers "parting out" with a list of mods that they need to get rid of in order to turn in their leased car.

The car is leased...why not lease the parts as well? :: suspensions, chips, brakes, wheels, exhausts....you name it.

Would you pay for this service? Say if it included installation of the parts and uninstall before trade in.

Let me know your thoughts!

I think your on to a good idea. You'd lease the parts to people then after take them off and sell them. If something breaks because of the mods, you have to take that in to consideration also. Because like if you tune a 335i, then the turbos blow and they bring it to the dealership, they won't get fixed. You could have a service I guess that if something breaks you will un install for the to bring it to service.